The present invention relates to an airbag and an airbag apparatus for protecting a human body in an emergency of a car crash or the like by means of expansion, and more particularly and preferably relates to the airbag and the airbag apparatus provided in a steering wheel of a motor vehicle.
In an emergency of a car crash or the like, various kinds of airbag apparatuses, such as that for use in a driver's seat or the like, are employed so as to protect an occupant. The airbag apparatus for use in the driver's seat is provided with an airbag formed by stitching up peripheral portions of a front panel at an occupant side and a rear panel at an opposite side together. An opening for engaging an inflator to receive a tip end side of the inflator is provided at a center of the rear panel. A periphery of the opening is attached to a retainer by means of a bolt, a pin, and a rivet or the like. In the rear panel, a venthole is provided for absorbing an impact caused by the occupant seated on the driver's seat when hitting the airbag, by discharging gas in the airbag.
In Japanese Unexamined Patent Application Publication Nos. 1-311930 and 1-81191, an airbag in which an inner panel (called “inside gas bag” in the Japanese Unexamined Patent Application Publication No. 1-311930) is provided in a manner so as to hang across an opening for an inflator in a rear panel, and a front panel, and in which space in the airbag is partitioned into a first chamber at a center and a second chamber surrounding the first chamber, is described. A continuous opening that allows the first chamber to communicate with the second chamber is provided in the inside gasbag. When the inflator is activated, the first chamber is expanded first, and the second chamber is then expanded in a serial manner.
Accordingly, it is an object of the present invention to provide an airbag whose internal portion is partitioned into a first chamber and a second chamber by means of an inner panel being connected to a front panel of the airbag so that the second chamber of the airbag to be promptly expanded at a time when the airbag is expanded.
Further objects and advantages of the invention will be apparent from the following description of the invention and the associated drawings.